Injection process

ABSTRACT

A method of injecting a plural component synthetic resin into a site where pressure and other conditions vary. A very high viscosity non-Newtonian fluid and a relatively low viscosity fluid are accurately metered in a proportioning pump system so that a small amount of the thin fluid and a large amount of the viscous fluid are supplied simultaneously to a blending device. Heat generating conditions of viscous shear are utilized in the blending device so that there is a substantial reduction in pressure across the blending device and a substantial elevation in temperature due to the internal heat generated by the viscous shear. The pressure on the resultant admixture is measured at the injection site, and the rate of fluid flow is adjusted to maintain that pressure at an approximate predetermined value. Injection is carried out at a predetermined elevated temperature. A substantial proportion of the heat required to elevate the temperature to the desired value is generated by viscous shear within the viscous component.

O Umted States Patent 11 1 1111 3,776,525

Warner Dec. 4 1973 INJECTION PROCESS [57] ABSTRACT [76] Inventor: James2732 Hamster Tera A method of injecting a plural component syntheticGlenda-1e Cahf- 91206 resin into a site where pressure and otherconditions [22] Filed; Man 26, 1973 vary. A very high viscositynon-Newtonian fluid and a relatively low viscosity fluid are accuratelymetered in PP 344,860 a proportioning pump system so that a small amountof the thin fluid and a large amount of the viscous 52 US. Cl. 259/7,259/149 fluid are Supplied simultaneously to a blending device- 51 In.CL B0" 3 10 o 5 04 o 15 04 Heat generating conditions of viscous shearare uti- [58] Field of Search 259 107, 109, 110, in the blending deuceso that there is a Substan- 259/148, 149, 7 9, 10 tial reduction inpressure across the blending device and a substantial elevation intemperature due to the [56] References Cited internal heat generated bythe viscous shear. The pressure on the resultant admixture is measuredat the in- UNITED STATES PATENTS jection site, and the rate of fluidflow is adjusted to 3,203,675 8/1965 Ward 259 maintain that pressure atan approximate predetep gi et mined value. Injection is carried out at apredeter- 3595627 7/1971 259/9 mined elevated temperature. A substantialproportion 3 727 892 4 1973 Notte et a1..2.....................::: 59/l0the heat required to elevate the temperature to the desired value isgenerated by viscous shear within the Primary ExaminerWilliam 1. Pricevlscous component- I Att0rney-Vemon D. Beehler et al. 11 Claims, 5Drawing Figures 7 If i t 1 7Z- Lat/,9

INJECTION PROCESS Previously, considerabledifficult'y was experienced inthe pressure injection of grout materials and particularly syntheticresins into unprepared sites. Particular difficulty had been experiencedin the pressure injection of foaming synthetic resins into structuralcracks and voids in concrete and masonry structures. This problem isparticularly acute where concrete and masonry structures sustain damagedue to movement.

caused by such factors as earth slippage or earthquakes. Where thestructure is not sufficiently damaged to necessitate completedemolition, restoration must of necessity include the rebonding of thedamaged sections.

According to the present invention, rebonding of structural cracks andvoids in concrete and masonry structures is accomplished utilizing amultireactantsynthetic resin. In general the multireactant syntheticresins used in the present process comprise at least one extremelyviscous non-Newtonian fluid loaded with substantial portions of solidsand semisolids and which is conveniently described as being a generallyliquid reactant. A second component of the multireactant synthetic resinis generally a low viscosity fluid. The pro portions of the twogenerally liquid reactants required to produce the desired syntheticresin are such that the quantity of the high viscosity reactant is atleast about 5 times greater than the quantity of the low viscosityreactant. The proportion of high viscosity reactant generally rangesfrom about 5 to 30 times greater than the quantity of the low viscosityreactant and is usually in the range of from about to times greater. Aproportioning pump system is used to supply the generally liquidreactants to a mixing or blending station in a precise predeterminedratio. The proportioning pump system employs positive displacement pumpsso that the ratios of the reactants may be maintained at predeterminedvalues. The proportioning. pump system is controlled so that the rate offlow from this system may be varied throughout a wide range withoutchanging the proportions of the reactants that are discharged from theproportioning pump system. i

The reactants are directed as independent pressurized streams into ablending device wherein the streams are combined and blended together toproduce a synthetic resin having the desired characteristics. The admixture of reactants that is produced in the blending device is injectedinto a generally predetermined location.

Injecting fluid materials into cracks or voids in a damaged structurerequires that the injection system and procedure be adopted toaccommodate a wide variety of conditions within the structure. Thepressure within the structure against which the reactants must beinjected varies widely depending upon the characteristics of the cracksand voids into which the intimate admixture of reactants must be forcedto flow. The intimate admixture must penetrate the cracks and voids withease.

According to the present invention, the pressure on the intimateadmixture of reactants in the blending device immediately adjacent theinjection port is monitored. and the flow rate of the reactants isadjusted so as to maintain this pressure at approximately a constantpredetermined value. When this pressure declines from the predeterminedvalue, the pumping rate is increased so as to increase the rate of flowand elevate the pressure. When the pressure rises, the pumping rate isdecreased so that the rate of flow decreases and the pressure declinesto the predetermined value.

The blending conditions in the blending device or mixing station aresufficiently severe to. insure that a substantially homogeneousadmixture will be produced in the blending device. The conditions aresuch that the internal heat generated in the highly viscous fluid alonedue to viscous shear is sufficient to elevate the temperature of thehighly viscous component by at least about 3 F. Also, the pressure dropacross the blending device is at least about 5 pounds per square inch.These values are determined by pumping only the highly viscous reactantthrough the system so as to avoid the influences of the heat generatedby the reaction of the reactants as well as any volumetric changesproduced by that reaction. The temperature elevation due to the internalgeneration of heat ,by viscous shear decreases the viscosity of theadmixture and also increases the rate of reaction. The penetrability ofthe admixture is also im proved by the violent blending actionimmediately prior to injection. The ability of the intimate admixture ofreactants to penetrate through cracks and voids for a substantialdistance away from the injection site improves as the violence of themixing or blending is increased.

In general, it is desired to elevate the temperature of the reactants tosome predetermined value and to inject them at that temperature. Therate of reaction and the viscosity of the materials at the time ofinjection are controlled by operating at a predetermined injectiontemperature. In addition to the temperature rise induced by mixing orblending at the mixing station, it may be desirable to preheat at leastthe highly viscous material before it is supplied to the proportioningpump system. This preheating is conveniently accomplished by stirringthe highly viscous material under conditions of viscous shear so as togenerate heat internally in the highly viscous material. It has beenfound that preheating the highly viscous material by mixing improves thepenetrability of the intimate admixture over that of an otherwiseequivalent system where preheating is accomplished by heat transfer fromsome external source. Also, the highly viscous material is generallyloaded with solids and semisolids so that-stirring improves thehomogeneity of the reactant.

The pressure under which the material is injected is generally providedby the proportioning pump system and is carried through the blendingdevice to the injection location. The highly viscous materialexperiences a pressure drop in the lines leading to the blending ormixing device which is generally proportionate to the length of the lineat a given pumping pressure. The maximum injection pressure is generallydictated by the nature of the structure into which the reactants arebeing injected. In general, concrete and masonry structures will bedamaged if the injection pressure is allowed to rise above approximately40 pounds per square inch. In general, the pressure drop across themixing device ranges from approximately 5 to 30 pounds per square inch.Because of the pressure drops in the lines and across the blendingdevice, it is generally desirable to provide a proportioning pump systemwhich will deliver upwards of 250 pounds per square inch on the outletside of the pump. A pump pressure of 250 pounds per square inch isgenerally sufficient to insure that it will be possible to maintain aninjection pressure of approximately 40 pounds per square inch, ifdesired.

The capacity of the system to operate continuously using an in-linemixer as the blending device with a fixed predetermined ratio ofreactants to one another, while maintaining the injection temperatureand pressure at approximately predetermined values assures that thestructural repairs will be of a predictable, uniform quality andcharacteristic.

In the drawings there is illustrated:

FIG. 1, a plan view of an embodiment of the in-line mixing equipmentaccording to this invention;

FIG. 2, a partial elevational view of a mixer taken along line 22 ofFIG. 1;

FIG. 3, a partial elevational cross section of the mixer illustrated inFIG. 1;

FIG. 4, a front elevation sectional view taken along line 4-4 of FIG. 3;and

FIG. 5, a front elevation sectional view taken along line 55 in FIG. 3.

In-line mixer includes an air motor 12 and a barrel 14. Air motor 12 isconnected with a suitable source of air (not shown) for driving purposesby means of air supply line 16. Air exhaust line 18 carries away spentair. Barrel 14 is provided with an internal bore 20, which extendsaxially of barrel 14. Rotor 22 is rotatably mounted in internal bore 20.Barrel 14 is threadably connected to air motor 12 so that internal bore20 extends coaxially with the drive shaft of air motor 12. Rotor 22 isprovided with flights of vanes 24, 26, 28, 30, 32, 34, and 36. Each ofthe flights of vanes 24 through 36 is provided with a plurality ofblades 38. The flights of vanes 24 through 36 respectively are mountedon shaft 40 and project radially therefrom at longitudinally spacedlocations. One end of shaft 40 is removably connected to the drive shaftof air motor 12 by means of drive coupling 66. The remote end of shaft40 is journaled on hollow support shaft 68. Inlet port 42 is providedadjacent the first flight of vanes 24 between the flights of vanes 26and 24. Inlet port 42 opens radially into the axial opening of shaft 40and communicates with the axial opening of hollow support shaft 68. Theend of barrel 14, which is axially remote from the threaded connectionto air motor 12, is provided with first reactant port 44, secondreactant port 46, first purge port 48, and second purge port 50. Each ofports 44 through 50, respectively, opens into internal bore 20 on theaxially remote side of first flight of vanes 24. The lines to whichreactant ports 44 and 46, respectively, are connected exteriorly ofbarrel 14 are provided with ganged valves 52. Ganged valves 52 aremounted on axially aligned shafts 54 and are actuated by a commonactuating handle 56. Ganged valves 52 are mechanically linked togetherso that they are opened and closed together. Provisions are made forpurging in-line mixer 10 in that purge ports 48 and 50 are connectedwith suitable sources of purging fluid (not shown) by means of linesattached to purge ports 48 and 50, respectively. The flow of purgingfluid to first purge port 48 is controlled by first purge valve 58, andthe flow of purging fluid to second purge port 50 is controlled bysecond purging valve 60. A discharge port 62 opens radially throughbarrel 14 between sixth flight of vanes 34 and seventh flight of vanes36. Discharge port 62 is connected to an injection location indicatedgenerally at 72 by means of injection coupling 70. A pressure gauge 64is provided on barrel 14 for visually indicating the pressure withininternal bore 20.

In operation, in-line mixer 10 is particularly adapted for use ininjecting a multireactant synthetic resin against a varying dischargepressure in injection location 72. In-line mixer 10 is particularly welladapted for use with foaming synthetic resins where the reactants arebrought together under pressure and intimately blended together underconditions of extremely violent viscous shear and stream splittingimmediately prior to being injected into injection location 72.

In-line mixer 10 is placed in operation by actuating air motor 12 whichacts through drive coupling 66 to cause the rotation of rotor 22 withininternal bore 20 of barrel l4. Actuating handle 56 is moved so thatganged valves 52 are moved by common shaft 54 from their closedconfiguration to their open configuration. Previously pressurizedreactants from sources not shown are thereby permitted to flowsimultaneously through first and second reactant ports 44 and 46,respectively. Generally, a high viscosity reactant is allowed to flowunder pressure into first reactant port 44, and a low viscosity reactantis allowed to flow into second reactant port 46. First reactant port 44discharges directly into the axially remote end of internal bore 20,while second reactant port 46 discharges into the axially hollowinterior of support shaft 68 which in turn discharges into the axiallyhollow portion of shaft 40 and through radially opening inlet port 42.Alternate flights of vanes 24 through 36, respectively, are arranged sothat their respective blades 38 are offset from the respective planes ofthe flights of vanes in alternate directions. For example, the blades infirst flight of vanes 24 are offset laterally from the plane of firstflight of vanes 24 so that when shaft 40 is rotated clockwise, as viewedin FIG. 5, the leading edges of blade 38 extend generally toward theremote end of barrel 14, and the trailing edges of blades 38 extendgenerally toward the other end of barrel 14. By contrast, the blades ofsecond flight of vanes 26 are twisted out of the plane of second flightof vanes 26 so that upon the counterrotation of shaft 40, as viewed inFIG. 5, from the remote end of barrel 14 the leading edges of blades 38extend toward the other end of barrel 14 and the trailing edges ofblades 38 extend toward the remote end of barrel 14. This arrangement ofalternating blade arrangements is continued throughout the balance offlights of vanes. The reactants are forced through in-line mixer 10,responsive to the pressure supplied by remote sources (not shown) thatact independently upon the respective reactants before they enter ports44 and 46, respectively. The reactants are subjected to violent forcesby the action of the counterset blades of rotor 22 as they are forcedthrough the in-line mixer 10. The blending action is so violent that thetemperature of the admixture is elevated substantially above thetemperature of the independent reactants by the time it reachesdischarge port 62.

In general, the flow of the reactants through the inline mixer occursprimarily between the blades 38. In one embodiment the openings betweenblades 38 are approximately one-sixteenth of 1 inch, and the diameter ofthe bore is approximately 1% inches. Seven flights of vanes areprovided, and the internal bore is approximately 10 inches long. Thereactants employed are widely diverse in their viscosities andproportions. The reactants are supplied by a proportioning pump system(not shown) under positive pressures such that the resultant admixtureconsists of approximately 5 percent of the low viscosity reactant andabout 95 percent of the high viscosity reactant. The viscosity of thelow viscosity reactant is approximately centipoises, and the viscosityof the high viscosity reactant is approximately 30,000 centipoises inthis specific embodiment.

After injection is complete-at injection location 72, injection coupling70 is disconnected and moved to another injection location, or purgevalves 58 and 60, respectively, are opened as desired, and ganged valves52 are closed. When purging of the system is complete, purge valves 58and 60, respectively, are closed, and the air supply to air motor 12 isdiscontinued.

The generally liquid reactants may include substantial quantities ofsolid phase material; such as, for example, blowing agents, extenders,pigments, fillers, and the like.

The proportioning pump systems, according to this invention, arecomprised of conventional metering pumps possessed of positivedisplacement characteristics so that the quantities of the variousgenerally liquid reactants that are supplied to the in-line mixer 10 maybe carefully controlled and proportioned at such predetermined ratios asmay be desired. The pressure from these positive displacement meteringpumps is carried through and is the expelling force which drives theblended admixture out of the discharge port 62.

The present invention is particularly applicable to those multireactantsynthetic resin systems in which the high viscosity reactant is employedin quantities of at least about 5 and preferably approximately at least10 times greater than the quantity of the low viscosity reactant.

The continuous blending is carried out under such violent conditionsthat, in addition to providing an intimate admixture of the reactants,the temperature of the admixture is elevated above that of theindividual reactants as supplied to the in-line mixer 10 by at leastabout 3 F. and preferably at least about 5 to 10 F. Blending isgenerally accomplished within a period of approximately 8 seconds andpreferably within a period of less than approximately 3 seconds. Thepressures at which the reactants are supplied to the in-line mixer aregenerally approximately equal and range from about 10 to about 50 poundsper square inch at the mixer inlet. The viscosity of the high viscosityreactant is generally at least approximately 100 times greater than theviscosity of the low viscosity reactant and may be as much asapproximately several thousand times greater than the viscosity of thelow viscosity reactant. The viscosities of the reactants areconveniently expressed in centipoises.

When it is not possible to accomplish the desired amount of temperatureelevation in the in-line mixer, the high viscous reactant may bepreheated. In. general, it has been found that injection of the materialis facilitated if the preheating of the high viscous reactant isaccomplished through vigorous stirring before the high viscosityreactant is supplied to the proportioning pump system.

The present invention is applicable to a wide variety of materials andis particularly applicable to multicomponent synthetic resins; such as,epoxy, polyester, polyurethane, and the like. Epoxy foam resin systemsare particularly well suited for use in the practice of the presentinvention. The viscosity at 60 F. of the high viscosity components ofresin systems, such as epoxy ceramic foaming resins, ranges fromapproximately 30,000 centipoises to 100,000 centipoises or more. Ingeneral, the viscosity of the low viscosity reactant at F. does notexceed 500 centipoises and is usually less than 300 centipoises. Theviscosity of the high viscosity reactant is usually at leastapproximately 50 times greater than the viscosity of the low viscosityreactant and is usually at least 100 times greater. The reactants areproportioned as is necessary to produce the desired synthetic resin. Ingeneral, the high viscosity generally liquid reactant constitutes amajor proportion of the combined reactants. The proportions by volume ofthe reactants may range from 2 to 20 or more parts by volume of the lowviscosity reactant to 100 parts by volume of the high viscosityreactant, but preferably the low viscosity reactant ranges from 3 to 9parts by volume to 100 parts by volume of the high viscosity reactant.

The heat generated internally of the admixture in the blending device isgenerally sufficient to raise the temperature of the high viscosityreactant by an amount ranging from about 5 to 20 F.

The reactiveadmixture from the blending device is injected immediatelyinto the predetermined injection site so that it will have time to flowand penetrate through the structure before the chemical reaction iscomplete.

The pressure drop and temperature rise across the blending device ismeasured using only the high viscosity component for test andcalibration purposes so that the heat of reaction and volumetric changesdue to the reaction do not interfere with the measurement of pressureand temperature change. In determining the de sired degree of mixing orstirring, consideration is given to the degree of penetrability of thereactive admixture into the wall as determined by taking core samplesfrom test sites. If adequate penetration can be achieved at apredetermined temperature and pressure without inducing the temperaturerise entirely by viscous shear within the viscous material, thereactants may be preheated by conventional heat transfer techniques, ifde sired. It is not possible, however, to achieve the desired degree ofpenetrability without altering the rheological properties of thematerial by mixing or stirring prior to injection.

The pressure at the injection site is measured adjacent the injectionport. As illustrated in the drawings, this pressure is measured adjacentdischarge port 62 by pressure gauge 64 on the upstream side of thesystem.

In general the rate at which reactants are supplied to the blender iscontrolled so as to achieve an approximately constant pressure at theinjection site. In some circumstances where there is a small volume ofvoid space to be filled in a damaged structure,'the void space is filledso rapidly that the injection system never reaches a steady state. Thepumping is carried out at a constant rate while the pressure increasesto some maximum predetermined value at which point pumping isdiscontinued.

The injection sites are prepared as to the injection location so as toprovide a means for connecting the system of the present invention tothe structure which is to receive the injection. Certain otherprocedures, such as vacuuming dust from structure cracks and sealingcracks or other openings in the surface of the structure, may be carriedout prior to injection, if desired.

What is claimed is:

1. Method for injecting a multireactant synthetic resin against avarying discharge pressure comprising:

selecting separate generally liquid reactants, which generally liquidreactants are adapted to being admixed and reacted together to form asynthetic resin, said generally liquid reactants including at least onelow viscosity reactant and at least one high viscosity reactant, theviscosity of said high viscosity reactant being at least approximately50 times greater than the viscosity of said low viscosity reactant, saidviscosities being expressed in centipoises;

continuously supplying each of said generally liquid reactants to amixing station under positive pressure, the quantities of said generallyliquid reactants that are supplied to said mixing station beingproportioned in a predetermined ratio so that the quantity of said highviscosity reactant is at least about times greater than the quantity ofsaid low viscosity reactant;

continuously blending said generally liquid reactants at said mixingstation under conditions sufficient to elevate the temperature of saidhigh viscosity reactant by at least about 3 F.; and

continuously injecting the resultant heated admixture responsive to saidpositive pressure into a predetermined location.

2. A method for injecting a multireactant synthetic resin according toclaim 1 including injecting the resultant heated admixture at anapproximate predetermined temperature and preheating at least the highviscosity reactant prior to blending the generally liquid reactants tosuch a temperature that the elevation of the temperature during saidblending is sufficient to achieve said approximate predeterminedtemperature.

3. A method for injecting a multireactant synthetic resin according toclaim 2 wherein said preheating is accomplished by subjecting thegenerally liquid high viscosity reactant to mechanical stirring ofsufficient intensity to cause said preheating.

4. A method for injecting a multireactant synthetic resin according toclaim 1 including conducting the blending of the generally liquidreactants under conditions such that the elevation of temperature of theresultant admixture is caused substantially entirely by said blending.

5. A method for injecting a multireactant synthetic resin according toclaim 1 including determining the pressure exerted by the resultantheated admixture prior to injecting said resultant heated admixture andadjusting the flow rate of the generally liquid reactants to the mixingstation to maintain said pressure at approximately a predeterminedvalue.

6. A method for injecting a multireactant synthetic resin according toclaim 1 wherein the generally liquid reactants are blended at the mixingstation under conditions sufficient to elevate the temperature of theresultant admixture by at least about 5 F. and reduce the pressure by atleast about 5 pounds per square inch.

7. A method comprising the steps of:

selecting a plurality of independent fluid components, which fluidcomponents are adapted to being reacted together to produce a syntheticfoaming resin, at least one of said fluid components being a highviscosity, non-Newtonian fluid having a viscosity in excess ofapproximately 30,000 centipoises at about F., and at least one other ofsaid fluid components being a low viscosity fluid having a viscosity ofless than approximately 300 centipoises at about 60 F.;

supplying said independent fluid components to a positive displacementproportioning pump system;

operating said positive displacement proportioning pump system toprovide said high viscosity, non- Newtonian fluid and said low viscosityfluid to a blending device in proportions of at least about 5 to 1,respectively; blending said fluid components into an intimate admixturein said blending device under conditions of heat generating viscousshear sufficient to elevate the temperature of the said high viscosity,non- Newtonian fluid by at least about 5 F.;

discharging said intimate admixture from said blending device;determining the pressure on said intimate admixture adjacent thelocation where said intimate admixture is discharged from said blendingdevice; and

maintaining said pressure at approximately a predetermined value byadjusting the rate of flow of said fluid components to said blendingdevice.

8. A method of claim 7 including generating sufficient heat by viscousshear in the high viscosity, non- Newtonian fluid during the practice ofsaid method to elevate the temperature of said high viscosity, non-Newtonian fluid by at least about 10 F.

9. A method of claim 7 including maintaining the pressure on theintimate admixture adjacent the location where the intimate admixture isdischarged from the blending device at between about 5 and 40 pounds persquare inch and wherein a pressure drop across said blending device isat least 5 pounds per square inch.

10. A method comprising the steps of:

selecting a plurality of independent fluid components, which fluidcomponents are adapted to being reacted together to produce a syntheticresin;

supplying said independent fluid components to a proportioning pumpsystem;

operating said proportioning pump system to supply said independentfluid components to a blending device in a predetermined ratio;

blending said fluid components into an intimate admixture in saidblending device under conditions sufficient to elevate the temperatureof said fluid components by at least about 5 F.;

discharging said intimate admixture from said blending device;determining the pressure on said intimate admixture adjacent thelocation where said intimate admixture is discharged from said blendingdevice; and

maintaining said pressure at approximately a predetermined value byadjusting the rate of flow of said fluid components to said blendingdevice.

11. A method comprising the steps of:

selecting a plurality of independent fluid compo nents, which fluidcomponents are adapted to being reacted together to produce a syntheticresin;

supplying said independent fluid components to a proportioning pumpsystem; operating said proportioning pump system to supply saidindependent fluid components to a blending device in a predeterminedratio;

,blending said fluid components into an intimate admixture in saidblending device under conditions 9 10 sufficient to elevate thetemperature of said fluid ture is discharged from said blending device;and components by at least about 5, R; maintaining said pressure at avalue up to an approxidischarging said intimate admixture from saidblendmate predetermined value by adjusting the rate of ing device; flowof said fluid components to said blending dedetermining the pressure onsaid intimate admixture 5 vice.

adjacent the location where said intimate admix-

1. Method for injecting a multireactant synthetic resin against avarying discharge pressure comprising: selecting separate generallyliquid reactants, which generally liquid reactants are adapted to beingadmixed and reacted together to form a synthetic resin, said generallyliquid reactants including at least one low viscosity reactant and atleast one high viscosity reactant, the viscosity of said high viscosityreactant being at least approximately 50 times greater than theviscosity of said low viscosity reactant, said viscosities beingexpressed in centipoises; continuously supplying each of said generallyliquid reactants to a mixing station under positive pressure, thequantities of said generally liquid reactants that are supplied to saidmixing station being proportioned in a predetermined ratio so that thequantity of said high viscosity reactant is at least about 5 timesgreater than the quantity of said low viscosity reactant; continuouslyblending said generally liquid reactants at said mixing station underconditions sufficient to elevate the temperature of said high viscosityrEactant by at least about 3* F.; and continuously injecting theresultant heated admixture responsive to said positive pressure into apredetermined location.
 2. A method for injecting a multireactantsynthetic resin according to claim 1 including injecting the resultantheated admixture at an approximate predetermined temperature andpreheating at least the high viscosity reactant prior to blending thegenerally liquid reactants to such a temperature that the elevation ofthe temperature during said blending is sufficient to achieve saidapproximate predetermined temperature.
 3. A method for injecting amultireactant synthetic resin according to claim 2 wherein saidpreheating is accomplished by subjecting the generally liquid highviscosity reactant to mechanical stirring of sufficient intensity tocause said preheating.
 4. A method for injecting a multireactantsynthetic resin according to claim 1 including conducting the blendingof the generally liquid reactants under conditions such that theelevation of temperature of the resultant admixture is causedsubstantially entirely by said blending.
 5. A method for injecting amultireactant synthetic resin according to claim 1 including determiningthe pressure exerted by the resultant heated admixture prior toinjecting said resultant heated admixture and adjusting the flow rate ofthe generally liquid reactants to the mixing station to maintain saidpressure at approximately a predetermined value.
 6. A method forinjecting a multireactant synthetic resin according to claim 1 whereinthe generally liquid reactants are blended at the mixing station underconditions sufficient to elevate the temperature of the resultantadmixture by at least about 5* F. and reduce the pressure by at leastabout 5 pounds per square inch.
 7. A method comprising the steps of:selecting a plurality of independent fluid components, which fluidcomponents are adapted to being reacted together to produce a syntheticfoaming resin, at least one of said fluid components being a highviscosity, non-Newtonian fluid having a viscosity in excess ofapproximately 30,000 centipoises at about 60* F., and at least one otherof said fluid components being a low viscosity fluid having a viscosityof less than approximately 300 centipoises at about 60* F.; supplyingsaid independent fluid components to a positive displacementproportioning pump system; operating said positive displacementproportioning pump system to provide said high viscosity, non-Newtonianfluid and said low viscosity fluid to a blending device in proportionsof at least about 5 to 1, respectively; blending said fluid componentsinto an intimate admixture in said blending device under conditions ofheat generating viscous shear sufficient to elevate the temperature ofthe said high viscosity, non-Newtonian fluid by at least about 5* F.;discharging said intimate admixture from said blending device;determining the pressure on said intimate admixture adjacent thelocation where said intimate admixture is discharged from said blendingdevice; and maintaining said pressure at approximately a predeterminedvalue by adjusting the rate of flow of said fluid components to saidblending device.
 8. A method of claim 7 including generating sufficientheat by viscous shear in the high viscosity, non-Newtonian fluid duringthe practice of said method to elevate the temperature of said highviscosity, non-Newtonian fluid by at least about 10* F.
 9. A method ofclaim 7 including maintaining the pressure on the intimate admixtureadjacent the location where the intimate admixture is discharged fromthe blending device at between about 5 and 40 pounds per square inch andwherein a pressure drop across said blending device is at least 5 poundsper square inch.
 10. A method comprising the steps of: selecting aplurality of independent fluid components, which fluid components areadapted to being reacted together to produce a synthetic resin;supplying said independent fluid components to a proportioning pumpsystem; operating said proportioning pump system to supply saidindependent fluid components to a blending device in a predeterminedratio; blending said fluid components into an intimate admixture in saidblending device under conditions sufficient to elevate the temperatureof said fluid components by at least about 5* F.; discharging saidintimate admixture from said blending device; determining the pressureon said intimate admixture adjacent the location where said intimateadmixture is discharged from said blending device; and maintaining saidpressure at approximately a predetermined value by adjusting the rate offlow of said fluid components to said blending device.
 11. A methodcomprising the steps of: selecting a plurality of independent fluidcomponents, which fluid components are adapted to being reacted togetherto produce a synthetic resin; supplying said independent fluidcomponents to a proportioning pump system; operating said proportioningpump system to supply said independent fluid components to a blendingdevice in a predetermined ratio; blending said fluid components into anintimate admixture in said blending device under conditions sufficientto elevate the temperature of said fluid components by at least about 5*F.; discharging said intimate admixture from said blending device;determining the pressure on said intimate admixture adjacent thelocation where said intimate admixture is discharged from said blendingdevice; and maintaining said pressure at a value up to an approximatepredetermined value by adjusting the rate of flow of said fluidcomponents to said blending device.